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Volume 47, Issue 2
Displaying 1-28 of 28 articles from this issue
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Chaomei MA, Norio NAKAMURA, Hirotsugu MIYASHIRO, Masao HATTORI, Kunita ...1999 Volume 47 Issue 2 Pages 141-145
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFrom CH2Cl2 and MeOH extracts of the stems of Cynomorium songaricum RUPR. (Cynomoriaceae), ursolic acid and its hydrogen malonate were isolated as inhibitors of human immunodeficiency virus type 1 (HIV-1) protease, with 50% inhibitory concentrations (IC50) of 8 and 6 μM, respectively. Amongst various synthesized dicarboxylic acid hemiesters of related triterpenes, inhibitory activity tended to increase in the order of oxalyl, malonyl, succinyl and glutaryl hemiesters, for triterpenes such as ursolic acid, oleanolic acid and betulinic acid. The most potent inhibition was observed for the glutaryl hemiesters, with an IC50 of 4 μM.From the water extract of the stems of C. songaricum, flavan-3-ol polymers, consisting of epicatechin as their extender flavan units, were also found to be potent inhibitory principles against HIV-1 protease.View full abstractDownload PDF (760K) -
Shin-ichi YAMADA, Ikuko TSUJIOKA, Takeji SHIBATANI, Ryuzo YOSHIOKA1999 Volume 47 Issue 2 Pages 146-150
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAn effective new route to diltiazem, a representative coronary vasodilator, through (-)-(2R, 3S)-3-(4-methoxyphenyl)glycidamide [(-)-2] has been achieved. The glycidamide (-)-2 was prepared in 43% overall yield by a combination of the enzymatic resolution of methyl (±)-(2RS, 3SR)-3-(4-methoxyphenyl)glycidate [(±)-1] with lipase and the following amidation of (-)-1 with ammonia. A one-pot synthesis through the treatment of (-)-2 with 2-aminothiophenol and a following ring closing reaction efficiently gave a key intermediate of diltiazem synthesis, (2S, 3S)-2, 3-dihydro-3-hydroxy-2-(4-methoxyphenyl)-1, 5-benzothiazepin-4(5H)-one [cis-(+)-5] in 80% overall yield.View full abstractDownload PDF (792K) -
Iwao SUZUKI, Maki ITO, Tetsuo OSA, Jun-ichi ANZAI1999 Volume 47 Issue 2 Pages 151-155
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA γ-cyclodextrin (γ-CyD) derivative (1) having a pyrene moiety, connected through a 4, 13-diaza-18-crown-6 ether moiety to γ-CyD, was synthesized and evaluated for guest binding and sensing properties. In aqueous solution, 1 existed as an association dimer in which the secondary hydroxyl sides faced each other to accommodate two pyrene moieties. Photo-induced electron transfer (PET) between the amino group and the excited pyrene moiety regulated the monomer fluorescence intensity of 1. The monomer-dimer equilibrium and the PET indicated that 1 may be used as a host capable of detecting guest complexation by changes in fluorescence intensity from the pyrene moiety. Deoxycholic acids were found to be good guests for detection by 1, and deoxycholic acid itself induced different fluorescence changes compared to the other deoxycholic acids. This indicated that 1 could recognize the position of the hydroxy groups on the steroidal framework. The azacrown part may participate in the guest selectivity for the deoxycholic acids by regulating the distance between the amino group and the pyrene moiety, modifying PET efficiency.View full abstractDownload PDF (810K) -
Farid WAHID, Claude MONNERET, Daniel DAUZONNE1999 Volume 47 Issue 2 Pages 156-164
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of about fifty novel 5-arylfuro[2, 3-d]pyrimidine derivatives were synthesized as potential inhibitors of dihydrofolate reductase (DHFR) arising from different species. Weak enzyme inhibition was observed for most of the compounds, with only a few reaching IC50 values less than 30 μM. With regards to antibacterial and antimalarial potency, only seven compounds showed a modest in vitro activity against some bacterial strains and only three products proved significantly active against P. falciparum.View full abstractDownload PDF (1392K) -
Takeshi SUZUKI, Hitoshi NAGAOKA, Hiromu HARA, Makoto TAKEUCHI, Munetos ...1999 Volume 47 Issue 2 Pages 165-170
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe metabolism of 2-(3-pyridyl)thiazolidine-4-carboxamides YM461 and YM264 was investigated, and their metabolites were compared with separately synthesized materials by measuring 1H-NMR spectra, mass spectra, and HPLC retention times, and evaluated for platelet activating factor (PAF) antagonistic activity. YM461 was metabolized by two different metabolic pathways (cleavage of the thiazolidine ring and oxidation of the benzyl position), whereas YM264 was metabolized by three metabolic pathways. The minor metabolite M7 from YM264 possessed potent PAF antagonistic activity, as strong as YM264 and this existed as an active metabolite. From pharmacokinetics studies, YM264 was almost completely absorbed from the gastrointestinal tract, but readily metabolized in rats. In dogs, pharmacokinetic parameters of YM264 were significantly improved compared to those in rats, and YM264 tended to show better pharmacokinetics than YM461 due to an extension of the half-life period.View full abstractDownload PDF (774K) -
Akimori WADA, Naoko FUJIOKA, Masayoshi ITO1999 Volume 47 Issue 2 Pages 171-176
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe synthesis of β-ionone analog tricarbonyliron complexes was investigated. N-Methoxy-N-methyl-(2, 6, 6-trimethyl-1-cyclohexen-1-yl)-2-propenamide (Weinreb amide), prepared from the corresponding ethyl ester and N, O-dimethylhydroxylamine hydrochloride, reacted smoothly with various organometallic reagents to afford the β-ionone analogs in good to excellent yields. Treatment of these compounds with dodecacarbonyltriiron afforded the corresponding tricarbonyliron complexes in high yields.View full abstractDownload PDF (948K) -
Nobuhide KAWASAKI, Hideki MIYATAKA, Mayumi NISHIKI, Hitoshi MATSUMOTO, ...1999 Volume 47 Issue 2 Pages 177-181
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA novel series of trimethylhydroquinone derivatives was synthesized and evaluated for their anti-lipid peroxidation activity in rat liver microsomes, inhibition of rat basophilic leukemia-1 (RBL-1) cell 5-lipoxygenase and 48h homologous passive cutaneous anaphylaxis (PCA) activity in rats. 4-[4-[4-(Diphenylmethyl)-1-piperazinyl]butoxy]-2, 3, 6-trimethylphenol (9c) exhibited the ability to inhibit Fe3+-ADP induced NADPH dependent lipid peroxidation (IC50=5.3×10-7M), 5-lipoxygenase ((IC50=3.5×10-7M) and PCA reaction (57% inhibition at 100 mg/kg p.o.).View full abstractDownload PDF (839K) -
Hirokazu MATSUNAGA, Taro EGUCHI, Koji NISHIJIMA, Toshio ENOMOTO, Kazum ...1999 Volume 47 Issue 2 Pages 182-186
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo polymorphs (form I, form II) and amorphous form of candesartan cilexetil ((±)-1-(cyclohexyloxycarbonyloxy)ethyl 2-ethoxy-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-benzimidazole-7-carboxylate; TCV-116) were characterized by differential scanning calorimetry (DSC), powder X-ray diffractometry (XRD), IR spectroscopy, and solid-state NMR. The molecular motion of TCV-116 in three forms was investigated by solid-state NMR, and signals due to the terminal cyclohexane ring of TCV-116 in form II were affected by temperature, whereas those in form I were scarcely affected. At lower (-89°C) and higher temperature (80°C), sharp signals due to the cyclohexane ring in form II were observed, whereas shallow signals were observed in the medium temperature range. These results indicated that the cyclohexane ring in form II presumably existed as the stable conformer : the chair form at lower temperature, and the chair form-chair form conformational change occurred at higher temperature. At the medium temperature, the broad and weak signals assigned to the cyclohexane ring in form II were presumably due to the flip-flop motion (correlation time being 10-4-10-5s) between the chair and boat forms. Results from the X-ray diffraction pattern and the crystal density also suggested that "free volume" for the flexible motion of the cyclohexane ring was present for form II.View full abstractDownload PDF (755K) -
Riichiro UCHIDA, Ayako NASU, Shoichi TOKUTAKE, Kouichi KASAI, Koichiro ...1999 Volume 47 Issue 2 Pages 187-193
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSFifteen new N-containing maltooligosaccharides were obtained using the chemoenzymatic method. Among these compounds, maltooligosaccharides having 6-amino-6-deoxy-D-sorbitol residue, (3R, 4R, 5R, 6S)-hexahydro-3, 4, 5, 6-tetrahydroxy-1H-azepine residue, and (3R, 5R)-3, 4, 5-trihydroxypiperidine residue at the reducing end showed strong inhibitory activities for human pancreatic α-amylase (HPA) (EC 3.2.1.1) and human salivary α-amylase (HSA). The administration of (3R, 4R, 5R, 6S)-hexahydro-3, 5, 6-trihydroxy-1H-azepine-4-yl O-α-D-glucopyranosyl-(1→4)-α-D-glucopyranoside (13, IC50=4.3×10-5M for HPA, IC50=8.2×10-5M for HSA) and (3R, 5R)-3, 5-dihydroxypiperidine-4-yl O-α-D-glucopyranosyl-(1→4)-α-D-glucopyranoside (18, IC50=3.4×10-5M for HPA, IC50=4.6×10-5M for HSA) to ICR mice suppressed postprandial hyperglycemia.View full abstractDownload PDF (1015K) -
Sandrine VENDEVILLE, Eric BUISINE, Xavier WILLIARD, Joseph SCHREVEL, P ...1999 Volume 47 Issue 2 Pages 194-198
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSTwo orthogonal peptide combinatorial libraries were screened to discover inhibitors of Tc80 protease, a novel target from Trypanosoma cruzi involved in host cell invasion. These libraries were composed of 15625 structurally diversified tripeptides, partitioned in 125 mixtures. The screening led to a low micromolar inhibitor which was actually an HF cleavage by-product H-Ipe-D-Tic-D-Glu(S-paratolyl)-OH. IC50 values of several analogous molecules of this hit were determined and are discussed. For the best compounds, conformational analysis revealed a high degree of similarity in shape with a potent prolylendopeptidase inhibitor, SUAM-1221.View full abstractDownload PDF (860K) -
Naoyoshi KOBAYASHI, Izumi SAITOH1999 Volume 47 Issue 2 Pages 199-202
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe established an in vitro drug release test for ointments, using oxybenzone as a model drug. At first, we concentrated upon the reproducibility of the results, the effects of the receiver solution composition, and the effects of the sample loading weight to fix the conditions for the in vitro drug release test.Once the conditions for the test were fixed, we examined the validity of the test by evaluating ointments containing oxybenzone at concentrations of 0.11-15.1%. In this study, we applied T. Higuchi's equation directly to the soluble-type ointment to maintain continuity.Then, for crystal-dispersion type ointments, the diffusion coefficient was calculated by applying the solubility determined by cone mesh filtration method to T. Higuchi's equation. For soluble-type ointments, the diffusion coefficient was calculated by applying a modification of T. Higuchi's equation. Consequently, apparent diffusion coefficient (Dapp) showed constant values, irrespective of the state of the drug (soluble or crystal dispersion). Thus, a validity of Dapp was suggested.Moreover, the theoretical curve of slope fitted well to the observed values in practical drug concentration levels up to 10%. It was suggested taht this in vitro drug release test for ointments is a useful and practical method for quality assurance specifications.View full abstractDownload PDF (668K) -
Masahito MIYAMOTO, Kaoru HIRANO, Hideki ICHIKAWA, Yoshinobu FUKUMORI, ...1999 Volume 47 Issue 2 Pages 203-208
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSGadolinium-containing lipid emulsions for neutron-capture therapy were designed to fulfill the following requirements : particle size smaller than 100 nm; gadolinium content as high as possible; surface of the emulsions modified with hydrophilic moieties to provide prolonged circulation in the blood. Emulsions containing soybean oil, water, Gd-diethylenetriaminepentaacetic acid-distearylamide (Gd-DTPA-SA), as an amphiphilic drug, and hydrogenated egg yolk phosphatidylcholine (HEPC), as an emulsifier, in a weight ratio of 7.36 : 92 : 1 : 2 were prepared without co-surfactants by the thin-layer hydration method using a bath-type sonicator. The mean particle size of the emulsions was 280.7 nm. In order to make the droplet size of the emulsions smaller than 100 nm, as well as to modify the emulsion surfaces, a co-surfactant, Tween[○!R] 80, HCO[○!R]-60, Pluronic[○!R] F68, polyoxyethylene alkyl ether (Brij[○!R]) or polyoxyethylene alkyl ester (Myrj[○!R]), was introduced into the standard system. Tween 80, HCO-60, Brij 76, 78 and 700 were effective in reducing the particle size to below 100 nm when the co-surfactant weight ratio (CWR), defined as co-surfactant/(HEPC+Gd-DTPA-SA) (w/w), was larger than 0.67; the particle size with Tween 80 and HCO-60 was reduced to 52.7 and 74.7 nm, respectively, at a CWR of 1.0 (w/w). In order to increase the gadolinium content, the weight ratio of Gd-DTPA-SA to HEPC was increased from 1 : 2 of the standard-Gd formulation to 2 : 1 of the high-Gd formulation. The measured particle size of the HCO-60 high-Gd emulsions was 78.7 nm when the CWR was 1.0 (w/w). In this case, the calculated gadolinium content reached 3.0 mg Gd/ml. These results indicate that HCO-60 is an effective co-surfactant not only in terms of particle size reduction but also with respect to gadolinium enrichment.View full abstractDownload PDF (1011K) -
Tetsuya TAKEYA, Manabu KAJIYAMA, Chikara NAKAMURA, Seisho TOBINAGA1999 Volume 47 Issue 2 Pages 209-219
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe have investigated the total synthesis of (±)-plumbazeylanone (1), a naphthoquinone trimer based on two different pathways (I) and (II). The synthetic approach based on pathway (I) was not successful. However, the first synthesis of 1 from plumbagin (2a) was achieved by utilizing an unsymmetrical methylene-bridged dimer (20b), with a naphthoquinone unit and a naphthalene unit as a key intermediate, based on pathway (II), in 11 steps with an overall yield of 5.9%. This synthesis features regioselective nucleophilic 1, 2-addition of the naphthyllithium reagent 4a to the C-1 position of naphthoquinone 20b, and the regio- and stereoselective dienone-phenol-type rearrangement of the 1, 2-adduct 21b (1, 2-migration of the naphthyl group to the C3-position on 21b) with 2 N-NaOH.View full abstractDownload PDF (1723K) -
Toshio YAJIMA, Nobuo UMEKI, Shigeru ITAI1999 Volume 47 Issue 2 Pages 220-225
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe effects of operating conditions in the spray-congealing process on the release and the micromeritic properties of clarithromycin (CAM) wax matrix were evaluated. CAM wax matrix with 30% CAM, 60% glyceryl monostearate (GM) and 10% aminoalkyl methacrylate copolymer E (AMCE) was manufactured at various atomizer wheel speeds and liquid feed rates with a spray dryer. Release of CAM from the matrix exhibited a two-phase pattern, probably due to the dissolution of the fine portions broken on the surface of the matrix. The slope and the extrapolated y-intercept of the subsequent release pattern were defined as the release rate and the initial amount of release of CAM from the matrix, respectively. These release parameters, as well as the volume median diameter and the specific surface area of matrix, were selected as response variables, and multiple regression analysis was performed. For specific surface area and initial amount of release, a minimum point was observed on the contour curve when the atomizer wheel speed was constant and the liquid feed rate was varied. For the release rate, a maximum point was observed on the contour curve under the same conditions. These points were considered preferable for masking the bitter taste of CAM preparation. Microscopic observation revealed that a small spherical matrix with a smooth surface could be obtained with a high atomizer wheel spped and optimum liquid feed rate. This matrix also possessed excellent properties for taste masking, with small initial amount of release and subsequent high rate of release.In conclusion, the congealing speed of melt droplets was the dominant factor in masking the bitter taste of CAM.View full abstractDownload PDF (1652K) -
Koki ISHIBASHI, Katsuyoshi NAKAJIMA, Yuki SUGIOKA, Mitsuo SUGIYAMA, Ta ...1999 Volume 47 Issue 2 Pages 226-240
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 2-phenylbenzofuran derivatives with a carbamoyl, alkylamino, or alkyloxy group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5α-reductase inhibitory activities in vitro. Against rat enzyme, the carbamoyl derivatives had more potent inhibitory activities than the alkylamino or alkyloxy derivatives, and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl derivatives. Against human enzyme, the 6-substituted derivatives had more potent inhibitory activities than the 5-substituted derivatives. The 6-carbamoyl and 6-alkylamino derivatives tended to show stronger inhibitory activities against human type 1 enzyme than against type 2 enzyme, but they were not largely selective.View full abstractDownload PDF (2200K) -
Yasuyuki KITA, Masahiro EGI, Makoto OHTSUBO, Toyokazu SAIKI, Akiko OKA ...1999 Volume 47 Issue 2 Pages 241-245
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSNovel and efficient syntheses of quinone imine ketals (2a-j) and quinone imines (4a-h) from substituted phenol ethers (1a-k) bearing an alkyl azido side-chain using the combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA) and trimethylsilyl trifuoromethanesulfonate (TMSOTf), have been developed.View full abstractDownload PDF (793K) -
Akira MIZUNO, Norio INOMATA, Mikiko MIYA, Tomoe KAMEI, Makoto SHIBATA, ...1999 Volume 47 Issue 2 Pages 246-256
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSA series of 1-aminoalkyl-pyrrolo[2, 3-c]azepin-8-one derivatives was synthesized and evaluated as α1 adrenergic and serotonin 2 (5-HT2) receptor antagonists, with the aim of finding a novel antihypertensive agent potently exhibiting both activities. Some compounds with a 4-[4-(4-fluorobenzoyl)piperidino]butyl group at the 1-position exhibited both activities, and varied significantly in terms of the substituents at the 4-position of the pyrroloazepine ring. Among the compounds obtained in this study, (E)-1-[4-[4-(4-fluorobenzoyl)piperidino]butyl]-4-hydroxyimino-7-methyl-1, 4, 5, 6, 7, 8-hexahydropyrrolo[2, 3-c]azepin-8-one (15a, SUN9221) displayed potent α1-adrenergic antagonistic activity (pA2=8.89±0.21) and 5-HT2 antagonistic activity (pA2=8.74±0.22) in isolated guinea pig arteries. This compound exhibited antihypertensive activity and a duration of action equivalent to orally administered prazosin or doxazosin, 3 mg/kg, in conscious spontaneously hypertensive rats, as well as potent antiplatelet aggregation activity.View full abstractDownload PDF (1490K) -
Zhi-Hong JIANG, Reiko FUKUOKA, Fukiko AOKI, Takashi TANAKA, Isao KOUNO1999 Volume 47 Issue 2 Pages 257-262
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSIn the course of our continuing studies on the chemical constituents of Rhoipteleaceae from the chemotaxonomical point of view, twelve dammarane-type triterpene glycosides, chilianosides A-L, were isolated from the leaves of Rhoiptelea chiliantha DIELS et Hand.-MAZZ. (Rhoipteleaceae). Their structures were elucidated on the basis of spectral and chemical evidence. Chilianosides B-G possess hydroperoxyl groups in the molecules, whereas chilianosides H-L are the hydroxyl analogues of chilianosides B-G. All of the chilianosides have 20-R configurations.View full abstractDownload PDF (871K) -
Masao NAGAOKA, Makoto MORIO, Mitsuteru NUMAZAWA1999 Volume 47 Issue 2 Pages 263-266
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESS[3β, 7, 7, 17α-2H4]Androst-5-ene-17β, 19-diol (6) and [3, 3, 7, 7, -2H4]androst-4-ene-17β, 19-diol (15-d4) were synthesized as internal standards for gas chromatographic-mass spectrometric analysis of the 19-hydroxylation of androst-5-en-17-one (1) and its 4-ene isomer 2, inhibitors of estrogen biosynthesis, using human placental aromatase. Treatment of [7, 7-2H2]3β-tosylate 3 with Zn-NaI-D2O, followed by reduction with NaBD4, gave compound 6 (d4, 79.8 atom%). Compound 15-d4 was synthesized via 3β, 17β-dihydroxy-5-en-7-one 10 as a key intermediate. Deoxygenation of the 5-en-7-one 10 and [7, 7-2H2]17β-hydroxy-4-en-3-one 13-d2, produced from compound 10 in two steps, with AlCl2D2 was used for the deuterium labeling reaction, producing compound 15-d4 (d4, 93.5 atom%). The 19-oxygenation products of aromatase inhibitors 1 and 2 could be analyzed, after NaBH4 reduction, as the corresponding 17β, 19-diol bis-trimethylsilyl ethers using the internal standards 6 and 15-d4.View full abstractDownload PDF (748K) -
Tomofumi NISHIMURA, Chen ZHANG, Yasuhiro MAEDA, Naohiro SHIRAI, Shin-i ...1999 Volume 47 Issue 2 Pages 267-272
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAllylbenzylsulfonium S-methylides 8S and dibenzylsulfonium S-methylides 18S have been generated by the fluoride ion-induced desilylation of S-benzyl-S-[(trimethylsilyl)methyl](alk-2-enyl)sulfonium salts 4S and S-benzyl-S-[(trimethylsilyl)methyl](4-substituted benzyl)sulfonium salts 7S, and the isomerized products are compared with those of the corresponding N-methylides. S-Methylides 8S selectively rearrange toward the allyl groups (path a in Chart 2), whereas rearrangement to the benzyl groups (path b) competitively occurs in N-methylides 8N. Isomerization of S-methylides 18S to S-benzylides 19S and 20S competes with sigmatropic rearrangement to the benzyl groups (paths a and b in Chart 3), whereas the isomerization of N-methylides 18N is not observed.View full abstractDownload PDF (887K) -
Plasma-Induced Free Radicals of Polycrystalline Monocarbohydrates Studied by Electron Spin ResonanceYukinori YAMAUCHI, Masami SUGITO, Masayuki KUZUYA1999 Volume 47 Issue 2 Pages 273-278
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSWe report here special features of plasma-induced free radicals of monocarbohydrates such as α- and β-glucose on its comparison with those of amylose and cellulose. The simulated spectra disclosed that the observed spectra of α-glucose consist of four kinds of spectral components, two isotropic spectra [doublet (I) and (II)], assigned to a hydroxylalkyl radicals and an anisotropic spectrum [anisotropic doublet (a-D) (III)], assigned to an acylalkyl radical, and a large amount of dangling-bond site (DBS) (V) with an intermediate level of conversion which includes a mixture of ring-opened and/or conjugated structure of no structural significance. On the other hand, those of β-glucose consist of four kinds of spectral components, I, III, V and an anisotropic doublet of doublets (a-DD) spectrum (IV) assignable to the acylalkyl radicals.View full abstractDownload PDF (655K) -
Midori KASHIMA1999 Volume 47 Issue 2 Pages 279-283
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSuperoxide (O-2·) was reduced by the addition of superoxide dismutase (SOD : O-2·scavenger) and catechins. In competitive reactions utilizing different concentrations of spin-trap agent, the IC50 values of each sample were changed. With regard to the Cu2+/H2O2 and Fe2+/H2O2 reaction systems, metal chelater, hydroxyl radical (·OH) scavenger and catechins eliminated the levels of·OH. For the Cu2+/H2O2 reaction systems, the IC50 for·OH scavenger changed, but that for metal chelater and catechins did not. However, for the Fe2+/H2O2 reaction system, the IC50 for·OH scavenger and catechins changed, whereas that for metal chelater did not. The ESR signal for free Cu2+ was changed by addition of metal chelater and catechins. In hte spectrophotometer experiments, it was confirmed that the CuCl2 spectrum was changed by addition of metal chelater and catechins but not by·OH scavenger. Conversely, the FeSO4 spectrum was not changed by addition of·OH scavenger or catechins, but was altered by metal chelater. Lipid peroxidation was inhibited by catechins in a concentration-dependent manner.Therefore, it was suggested that the catechins did not scavenge directly the generated·OH from the Cu2+/H2O2 reaction system, but inhibited the generation of·OH by acting on the Cu2+/H2O2 reaction system. On the other hand, with respect to the·OH generated from the Fe2+/H2O2 reaction system, it was suggested that the catechins had a direct scavenging capacity of the·OH, but had little chelating activity of iron.It was confirmed that catechins have the ability to scavenge for O-2·as well as·OH and to inhibit the generation of·OH by chelation with metal ions.View full abstractDownload PDF (784K) -
Tadahiro TAKEDA, Yuji NARUKAWA, Noriyasu HADA1999 Volume 47 Issue 2 Pages 284-286
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThree antioxidative phenylethanoid glycosides and two new iridoid glycosides, along with three known iridoids were isolated from the African medicinal plant, Leonotis nepetaefolia R. BR. (Labiatae). The new iridoid glycosides were established as 10-O-(trans-3, 4-dimethoxycinnamoyl)geniposidic acid and 10-O-(p-hydroxybenzoyl)geniposidic acid. Antioxidative activities of the compounds were measured by α, α-diphenyl-β-picrylhydrazyl (DPPH) method, and the three known phenylethanoid glycosides, acteoside, martynoside and lavandulifolioside showed strong antioxidative activity.View full abstractDownload PDF (503K) -
Youying GUO, Keisuke KOJIMA, Lianbo LIN, Xiaowen FU, Changqi ZHAO, Kei ...1999 Volume 47 Issue 2 Pages 287-289
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSSeveral species of the general Tinospora (Menispermaceae) are widely distributed over Asia and Africa and are well-known for their medicinal properties. From the stems of Tinospora hainanensis, a new N-methyltetrahydroprotoberberine alkaloid, N-methyltetrahydrocolumbamine, was isolated and characterized on the basis of NMR, MS and X-ray.View full abstractDownload PDF (457K) -
Junei KINJO, Masafumi OKAWA, Manabu UDAYAMA, Yoshimi SHONO, Tomoki HIR ...1999 Volume 47 Issue 2 Pages 290-292
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe protective effects of oleanolic acid-type saponins and their derivatives on in vitro immunological liver injury of primary cultured rat hepatocytes were studied. A known antihepatotoxic saponin (chikusetsusaponin IVa, 1) showed hepatoprotective activity in this model. Although a rhamnosyl derivative (2) of 1 similarly showed hepatoprotective activity, its prosapogenin (5) did not show any hepatoprotective activity. On the centrary, 5 exhibited cytotoxicity toward liver cells. In the absence of antiserum, monodesmosyl saponins showed hepatotoxicity, while the bisdesmosyl saponins except for 1, did not show such hepatotoxicity. In order to clarify the effects of the sugar residues at C-3 and C-28 responsible for hepatoprotective and hepatotoxic actions, oleanolic acid 3-O-glucuronide (2a) and oleanolic acid 28-O-glucoside (2b) were prepared and tested. 2b showed neither hepatoprotective action nor hepatotoxicity. In contrast, 2a was effective at 90 μM on hepatoprotection, although it showed strong hepatotoxicity. Oleanolic acid (2c) itself showed both hepatoprotective action and weak hepatotoxicity. Therefore, the hepatoprotective activity of these types of saponins could represent a balance between hepatoprotective action and hepatotoxicity.View full abstractDownload PDF (563K) -
Fumiaki UEHARA, Masayuki SATO, Chikara KANEKO1999 Volume 47 Issue 2 Pages 293-294
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSπ-Facial selectivity in catalytic hydrogenation and conjugate addition of a series of 2, 2-disubstituted 4H-1, 3-dioxin-4-ones was examined. The results indicated that pyramidalization at the reaction center of dioxinones is less important than other stereoelectronic effects and the steric effect as the origin of π-facial selectivity.View full abstractDownload PDF (409K) -
Miwa KUBO, Ih-Sheng CHEN, Hiroyuki MINAMI, Yoshiyasu FUKUYAMA1999 Volume 47 Issue 2 Pages 295-296
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSAldovibsanin A (1), 7-epi-aldovibsanin A (2) and aldovibsanin B (3), novel vibsane-type diterpenes without a β, β-dimethylacrylate group, have been isolated from the leaves of Viburnum odoratissimum, and their structures have been elucidated by spectroscopic analyses and chemical correlation with vibsanin C (4).View full abstractDownload PDF (418K) -
Yasushi OISO, Masao TOYOTA, Yoshinori ASAKAWA1999 Volume 47 Issue 2 Pages 297-298
Published: February 15, 1999
Released on J-STAGE: March 31, 2008
JOURNAL FREE ACCESSThe methanol extract of the Japanese fern Hymenophyllum barbatum was chromatographed on Sephadex LH-20 and HPLC to give perrottetin H, an acyclic bis-bibenzyl derivative which has been isolated from the liverwort Jubula japonica. This is the first isolation and identification of bis-bibenzyl from the pteridophytes. The occurrence of bis-bibenzyl in both pteridophytes and liverwort is very important in determining the evolutionary ladder of both terrestrial spore-forming green plants.View full abstractDownload PDF (376K)
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